The phrase "a pair of shells" is correct and usable in written English.
It can be used when referring to two shells that are typically found together, such as in a natural setting or as part of a collection.
Example: "On the beach, I found a beautiful pair of shells that were perfectly matched in color and size."
Alternatives: "two shells" or "a couple of shells".
Another time, I asked him to identify a pair of bullet shells that I'd found in my back yard.
She had her arms wrapped around her chest, her hip bones were a pair of razor shells, and her pubic hair was surprisingly dark.
Highlighting security concerns even in areas under firm government control, the elections announcement came just hours after a pair of mortar shells stuck some 100 metres from the parliament building in central Damascus, killing five people, according to state TV.
First studied in 1733, because they were devouring the wooden pilings the Dutch used to protect their lowlands from flooding, the naked, cylindrical creatures (which are actually mollusks, not worms) bear a pair of tiny shells at one end of their bodies that they use to grind into wood.
In the capital, authorities reported that 14 civilians, mostly students, were killed and 86 injured when a pair of mortar shells struck an Islamic school in the Shaghour district in Damascus Old Cityy.
Lightly floured and sauteed, a pair of soft-shell crab were good enough, without being outstanding.
By E. J. Kahn The New Yorker, June 1 , 1946P. 61 A man buys a pair of tortoise shell glasses and everyone suspects him of being a Communist.
Cordeiro is represented in the show by the striking Visible Idea, a pair of interlocking shell-shapes on a crimson canvas.
TODAY'S OUTFIT A Kate Moss Topshop blouse, a vest from H&M, J Brand corduroys and a pair of Adidas shell tops that I've had for 13 years.
"If you're a rapper and you needed a pair of Adidas shell toes for your album-release party at 11 o'clock, call me," he said.
